Arbitrage#054

Kalshi-Polymarket Identical-Contract Relative Value

The same real-world question (a CPI inflation print, a Fed rate decision, an election result) is often listed on both Kalshi (a US-regulated exchange) and Polymarket (crypto-based). When the two venues disagree on the price, you buy the cheaper side on one and bet against it on the other, then hold both until they settle. Because one of them must be right, you lock in the difference. The edge is that the two platforms have separate, segmented user bases that keep prices out of line.

What you need to run it

Kalshi API + Polymarket CLOB feed with contract-mapping table
Resolution-criteria reconciliation to confirm payouts match
Capital on both venues incl. USDC and USD funding
FX/fee/withdrawal-timing cost model

Where this applies

Markets on Polymarket where kalshi-polymarket identical-contract relative value is the natural play:

Will CPI inflation exceed 3.0% year-over-year in the July 2026 print?
Will the Fed hold rates at the September 2026 FOMC meeting?
Will the Fed cut rates at the December 2026 FOMC meeting?

Capabilities this demands

Multi-venueData ingestionSignificant capitalDomain knowledge

At a glance

CategoryArbitrage

Requirements4

CapabilitiesMulti-venue, Data ingestion, Significant capital, Domain knowledge

VenuePolymarket (CLOB, Polygon)

Build it

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This is documentation, not advice. Poly Research & Robotics publishes how these strategies work because the method should be checkable — not as a recommendation to trade them. See the full strategy database (147 strategies) or the data resources directory.